Nature Nanotechnology, January 2011 Part I: Understanding Tissue.

Nanotechnology inCell and Tissue Engineering

Gregory DamhorstBIOE 506

April 25, 2011

Overview

Tissue Engineering Basics

Nanotechnology Methods

Design Examples

Nanomaterials

Nanodevices

Nature Nanotechnology, January 2011

TISSUE ENGINEERING BASICSPart I: Understanding Tissue

• Motivation: repair of damaged tissues and organs

• Used to think that the matrix simply defined tissue boundaries

• The key is in the ECM

Tissue

Engineering

Basics

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.

EXTRA-CELLULARMATRIX

Tissue

Engineering

Basics

Extracellular Matrix

Tissue

Engineering

Basics

Extracellular Matrix

• Protein fibres (collagen, elastin)• Adhesive protein (laminin,

fibronectin)• Polysaccharides (hyaluronic acid,

heparan sulphate)• Cell adhesion (integrin, cadherin)

Tissue

Engineering

Basics


Extracellular Matrix• The key is in the ECM– Topography– Mechanical Properties– Growth Factor Concentration– ECM Molecules

• The ECM promotes a unique microenvironment that fosters tissue organization

Tissue

Engineering

Basics


Tissue

Engineering

Basics

Extracellular Matrix• The key is in the ECM– Topography– Mechanical Properties– Growth Factor Concentration– ECM Molecules

• The ECM promotes a unique microenvironment that fosters tissue organization

control the ECM -> control the tissue


Tissue

Engineering

Basics


NANOTECHNOLOGY METHODSPart II: Fabricating the ECM

Nan

otec

hnol

ogy

Met

hods Electrospinning

• Simple• Usually at upper-range of

natural 50-500 nm fiber diameter

Self Assembly• Smaller fibers and pore

sizes• Can include functional

motifs – mechanical and instructive matrix support


Nan

otec

hnol

ogy

Met

hods Electrospinning

• Polymer solution charged and fed into electric field

• Carrier solution evaporates and fibrils are deposited on substrate

• http://www.youtube.com/watch?v=E1zuQEYGMJ0

Barnes, C.P. et al. Nanofiber technology: Designing the next generation of tissue engineering scaffolds. Adv. Drug. Deliv. Rev. 2007

http://www.youtube.com/watch?v=E1zuQEYGMJ0

Nan

otec

hnol

ogy

Met

hods Self-assembly

Zhang, S. Fabrication of novel biomaterials through molecular self-assembly. Nature Biotechnol. 2003.

Nan

otec

hnol

ogy

Met

hods Self-assembly:

Ionic Self-complementary peptide

• Peptide of 16 AA• Alternating polar/nonpolar• Form stable β-strands and β-sheets• Form nanofibers by hydrophobicity• Matrices with high H2O content


Nan

otec

hnol

ogy

Met

hods Self-assembly:

Surfactant-type peptide

• Charged head group and nonpolar tail• Form nanotubes and nanovesicles• Form interconnected network• Similar to carbon nanotube behavior


Nan

otec

hnol

ogy

Met

hods Self-assembly:

Surface nanocoating peptide

• Three regions:– Anchor– Linker– Functional Head

• Can be used in inkjet printer


Nan

otec

hnol

ogy

Met

hods Self-assembly:

Molecular switch peptide

• Strong dipoles• Conformation changes from α<->β• Could be coupled with metal

nanocrystals


Nan

otec

hnol

ogy

Met

hods Non-fibrous ECM components

• Adhesion proteins• Growth factors• Topography


Nan

otec

hnol

ogy

Met

hods Adhesion Proteins

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Re’em, T. The effect of immobilized RGD peptide in macroporous alginate scaffolds on TGFbeta1-induced

chondrogenesis of human mesenchymal stem cells. Biomaterials. 2010.

Matrix modified with adhesion proteins

Unmodified scaffold

Spreading and attaching to matrix

Only cell-cell adhesion

Nan

otec

hnol

ogy

Met

hods Growth Factors

• bFGF – Basic Fibroblast Growth Factor• Promotes angiogenesis

Freeman, I. The effect of sulfation of alginate hydrogels on the specific binding and controlled release of heparin-binding proteins. Biomaterials. 2008.

bFGF bound to scaffold

bFGF adsorbed to scaffold

bFGF absent

Nan

otec

hnol

ogy

Met

hods Topography

• Endothelial Cells

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Teixeira, AI. Epithelial contact guidance on well-defined micro- and nanostructured substrates. J. Cell. Sci. 2003.

Flat topography

Grooved topography

DESIGN EXAMPLESPart III: Designing a Scaffold

Cardiomyocytes

• ECM forces cardiomyocytes to couple mechanically

• Nanogrooved surface can force cell alignment in same way

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Kim, DH. Nanoscale cues regulate the structure and function of macroscopic cardiac tissue constructs. PNAS. 2010.

Epithelial Cells

• Epithelial cells are polarized and adhere to other cells

• Nanofibres modified with surface molecules can promote these effects

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Feng, ZQ. The effect of nanofibrous galactosylated chitosan scaffolds on the formation of rat primary hepatocyte aggregates and the maintenance of liver

function. Biomaterials. 2009.

Bone

• Osteoblasts influenced by bone matrix

• Nanostructures used to enhance osteogenesis

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Roohani-Esfahani, SI. The influence hydoxyapatite nanoparticle shape and size on the properties of biphasic calcium phosphate scaffolds coarted with

hydroxyapatite-PCL composites. Biomaterials. 2010.

NANOMATERIALSPart IV: Enhancing the Engineering Matrix

Nan

omat

eria

lsCarbon Nanotubes

• CNT sponges increase conductivity of matrix

• Also use to increase tensile strength

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Wang, S. F., Shen, L., Zhang, W. D. & Tong, Y. J. Preparation and mechanical properties of chitosan/carbon nanotubes composites. Biomacromolecules. 2005

Gui, X. et al. Soft, highly conductive nanotube sponges and composites with controlled compressibility.ACS Nano. 2010.

Nan

omat

eria

lsNanotitanate Wires

• Specially fabricated wires to promote cell-matrix adhesion

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Wu, S. L. et al. A biomimetic hierarchical scaffold: natural growth of nanotitanates on three-dimensional microporous Ti-based metals. Nano Lett. 2008

Nan

omat

eria

lsNanospheres

• Control the release of growth factors

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Zhang, SF. Nanoparticulate systems for growth factor delivery. Pharm. 2009.

Nan

omat

eria

lsGold Nanowires

• Control wire with electrophoresis and dielectrophoresis

• Control localization of biomolecules

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Fan, D. Subcellular-resolution delivery of a cytokine through precisely manipulated nanowires. Nature Nanotechnology. 2010.

Nan

omat

eria

lsPhage, magnetic iron oxide and gold nanoparticles

• Manipulate geometry of cell mass with 3D structure

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Souza, G. Three-dimensional tissue culture based on magnetic cell levitation. Nature Nanotechnology. 2010.

NANODEVICESPart V: Monitoring Tissue Development

Nan

odev

ices

Electrical Recording

• Penetrates cell membrane, measure intracellular signals

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Tian, B. Three dimensional, flexible nanoscale field-effect transistors as localized bioprobes. Science. 2010.

Nan

odev

ices

Biosensors

• Optical biosensor – photoluminescence differs by presence of drug or reactive species

Dvir, Tal, et al. Nanotechnological strategies for engineering complex tissues. Nature Nanotechnology. 2011.Heller, DA. Multimodal optical sensing and analyte specificity using single-walled carbon nanotubes. Nature Nanotech. 2009.

Summary

Tissue Engineering Basics

Nanotechnology Methods

Design Examples

Nanomaterials

Nanodevices

Nature Nanotechnology, January 2011

QUESTIONSThe End

Nature Nanotechnology, January 2011 Part I: Understanding Tissue.

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Transcript of Nature Nanotechnology, January 2011 Part I: Understanding Tissue.